Dynamic load balancing has been implemented in a concurrent one-dimensional electromagnetic plasma particle-in-cell (PIC) simulation code using a method which adds very little overhead to the parallel code. In PIC codes, the orbits of many interacting plasma electrons and ions are followed as an initial value problem as the particles move in electromagnetic fields calculated self-consistently from the particle motions. The code was implemented using the GCPIC algorithm in which the particles are divided among processors by partitioning the spatial domain of the simulation. The problem is load-balanced by partitioning the spatial domain so that each partition has approximately the same number of particles. During the simulation, the partitions are dynamically recreated as the spatial distribution of the particles changes in order to maintain processor load balance.

Long lifetimes are required for AMTEC (or sodium heat engine) components for aerospace and terrestrial applications, and the high heat input temperature as well as the alkali metal liquid and vapor environment places unusual demands on the materials used to construct AMTEC devices. In addition, it is important to maximize device efficiency and power density, while maintaining a long life capability. In addition to the electrode, which must provide both efficient electrode kinetics, transport of the alkali metal, and low electrical resistance, other high temperature components of the cell face equally demanding requirements. The beta{double_prime} alumina solid electrolyte (BASE), the seal between the BASE ceramic and its metallic transition to the hot alkali metal (liquid or vapor) source, and metallic components of the device are exposed to hot liquid alkali metal. Modification of AMTEC components may also be useful in optimizing the device for particular operating conditions. In particular, a potassium AMTEC may be expected to operate more efficiently at lower temperatures.

None

The purpose of the present task is to develop high temperature multi-foil insulation suitable for use in the SP-100 thermoelectric converter project. Part of this task involves careful examination of alternative foil and foil spacing materials with the goal of effecting significant weight savings over current state-of-the-art foil insulation. This task involved the determination of the state-of-the-art foils, ascertaining what data is available, what additional data is required, preliminary assessment of the suitability of alternate foil and spacer materials, and specific recommendations for additional tests required to qualify new and existing insulation designs for use in the SP-100.

A phase 2 study has been initiated to investigate surfactant- assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This report covers the fourth quarter of work. The major accomplishments were (1) Completion of coal liquefaction autoclave reactor runs and related analysis with Illinois {number_sign}6 coal with time as a variable at 375{degree}C, and pressures of 1800 psig; (2) an investigation into the mechanism of the effect that the lignosulfonate surfactant has in enhancing liquefaction yields; and (3) completion of a bench-scale test with the surfactant in the continuous flow Catalytic Two Stage Liquefaction Process (CTSL) reactor at HRI.

Born to meet the special needs of America`s space effort, the SP-100 Program testifies to the cooperation among government agencies. The Department of Energy (DOE), the National Aeronautics and Space Administration (NASA), and the Defense Advanced Research Projects Agency (DARPA) are working together to produce a 100-kW power system for use in outer space. At this point in the effort, it is appropriate to review: The approach to meet program goals; the status of activities of the Project Office, managed by the Jet Propulsion Laboratory (JPL); and, because this is a meeting on materials, answers beings developed by the Project Office to vital questions on refractory alloy technology.

This report covers the initial year`s effort in the development of an Operational Life Model (OLM) for the SP-100 Space Reactor Power System. The initial step undertaken in developing the OLM was to review all available documentation from GE on their plans for the OLM and on the degradation and failure mechanisms envisioned for the SP-100. In addition, the DEGRA code developed at JPL, which modelled the degradation of the General Purpose Heat Source based Radioisotope Thermoelectric Generator (GPHS-RTG), was reviewed. Based on the review of the degradation and failure mechanisms, a list of the most pertinent degradation effects along with their key degradation mechanisms was compiled. This was done as a way of separating the mechanisms from the effects and allowing all of the effects to be incorporated into the OLM. The emphasis was on parameters which will tend to change performance as a function of time and not on those that are simply failures without any prior degradation.

This document defines the top level requirements of potential users of a space based nuclear electric power supply. This provides the SP-100 Project and information required to design the modular (10-1000 KWe) space power systems to meet the needs of most potential users.

This report describes work to develop a state-of-the-art electron cyclotron resonance (ECR) plasma-enhanced chemical vapor deposition (PECVD) system. The objective was to understand the deposition processes of amorphous silicon (a-Si:H) and related alloys, with a best-effort improvement of optoelectronic material properties and best-effort stabilization of solar cell performance. ECR growth parameters were systematically and extensively investigated; materials characterization included constant photocurrent measurement (CPM), junction capacitance, drive-level capacitance profiling (DLCP), optical transmission, light and dark photoconductivity, and small-angle X-ray scattering (SAXS). Conventional ECR-deposited a-Si:H was compared to a new form, a-Si:(Xe, H), in which xenon gas was added to the ECR plasma. a-Si:(Xe,H) possessed low, stable dark conductivities and high photosensitivites. Light-soaking revealed photodegradation rates about 35% lower than those of comparable radio frequency (rf)-deposited material. ECR-deposited p-type a SiC:H and intrinsic a-Si:H films underwent evaluation as components of p-i-n solar cells with standard rf films for the remaining layers.

The original SP-100 conceptual system design was examined from the mechanical design and integration viewpoint for the purpose of updating the design, identifying concerns, and providing recommendations for future work. Some of the findings were that: Integration of heat pipes into the radiator structure appears practical, but a number of problems remain to be addressed and resolved through development effort; thermal and structural interfacing of the shield and defining shield weight are key areas that need to be addressed; the radiator may be critical in shell buckling which would make beryllium a leading candidate material; material problems such as beryllium vs. shuttle fracture mechanics criteria need to be addressed.

The practicality of using a thin-film styrene/acrylate copolymer electrophoretic coating to isolate concentrator cells electrically from their surroundings in a photovoltaic concentrator module is assessed. Only the electrical isolation problem was investigated. The approach was to subject various types of EP-coated aluminum specimens to electrical stress testing and to aging tests while monitoring coating electrical resistivity properties. It was determined that, in general, longer processing times--i.e., thicker electrophoretic layers--resulted in better voltage-withstand properties. In particular, a two-minute processing time seemed sufficient to provide the electrical isolation required in photovoltaic concentrator application applications. Even though electrophoretic coatings did not seem to fill voids in porous-anodized aluminum substrates, breakdown voltages generally exceeded hi-pot pass-fail voltage levels with a comfortable margin. 6 refs, 11 figs, 5 tabs.

This document addresses basic configurational tradeoffs associated with the SP-100 class of nuclear space power systems. In the SP-100 project, the three reference designs, fallback, baseline, and advanced, employ thermoelectric power conversion with different thermoelectric materials. This issue of the document presents results generated for the thermoelectric design as of the end of 1985. Emphasis is placed on showing general trends and the range of possibilities that could result from selection of a particular design. This document, which reflects efforts on 100-kWe reference designs as of the end of 1985, will be extended and updated to reflect progress in the design studies of the follow-on ground engineering phase for which a 300-kWe size has been selected. THere is a considerable flexibility to the SP-100 power system so that it will generally be most advantageous to tailor it to meet user requirements.

Nuclear space powerplants can operate at temperatures below 900 K and use stainless steel construction without a weight penalty if new radiator concepts can achieve radiator weights of 1-3 kg/m{sup 2}. Conventional tube-and-fin radiators weight about 10 kg/m{sup 2} because of heavy tube walls to prevent meteroid puncture. Radiator designs that do not require meteroid protection are possible; they operate with fluids of low vapor pressure that can be exposed directly to space in external-flow radiators. An example is the {open_quotes}rotating disk radiator{close_quotes} in which centrifugal force drives a liquid film radially outward across a thin rotating metal disk; meteroid punctures cause no loss of fluid other than from evaporation, which can be small. An even lighter concept is the liquid drop radiator in which heat is radiated directly from moving liquid drops. Such radiator concepts look practical, and they may be much easier to develop than the high-temperature, refractory-metal power systems necessitated by conventional radiators.

DARPA, in conjunction with DOE`s Office of Nuclear Energy, and NASA`s Office of Aeronautics and Space Technology are jointly sponsoring a space nuclear reactor power system program known as the Space Power-100 (SP-100) Development Project. The program is presently in the critical technology phase. This phase, better known as technology assessment and advancement, includes mission requirements definition, system conceptual designs, and critical technology development. A ground test phase decision is scheduled for July 1985. If the decision is positive, the next phase would begin in fiscal year 1986. An overriding concern in conducting this program is to ensure that nuclear safety is being properly addressed even in these early stages.

This report contains a discussion on many aspects of a nuclear electric propulsion planetary science mission and spacecraft using the proposed SP-100 nuclear power subsystem. A review of the science rationale for such missions is included. A summary of eleven nuclear electric propulsion planetary missions is presented. A conceptual science payload, mission design, and spacecraft design is included for the Saturn Ring Rendezvous mission. Spacecraft and mission costs have been estimated for two potential sequences of nuclear electric propulsion planetary missions. The integration issues and requirements on the proposed SP-100 power subsystems are identified.

The objective of this task was to establish and evaluate what PCC technologies need to be developed and what impact the availability and development of PCC technologies will have on Ground Demonstration Development Decision.

SP-100 is the designation for a nuclear reactor-based power plant being developed for both civil and military missions beginning in the 1990s for such potential space applications as communication satellites, space radar, electric propulsion and space stations. Typically, a system using the SP-100 along with a selected upper stage system would be launched by the National Space Transportation System (NSTS) Space Shuttle System into a near-earth orbit, deployed, and through upper stage propulsion burn(s) be inserted/transferred to its mission orbit. The nature of the advanced design SP-100 payloads using this power plant are physically and functionally compatible with the NSTS and meet the safety requirements thereof. The purpose of this document is to define and present the requirements and interface provisions that, when satisfied, will ensure technical compatibility between SP-100 systems and the NSTS.

None

From abstract: This report presents the theory and method of calculation used by MIX2, describes the input to the program, presents results of two test cases, and provides a program listing.

The last of the U.S. Army Soldier Shows "Blueprint Specials" to be published, "OK, USA" is a musical revue on the theme of U.S. soldiers returning to the United States and finding it finding it as foreign and exotic as any country overseas because they have been away and living under extreme circumstances for so long. Like the other "Blueprint Specials," this show includes a complete script (multiple copies this time); a conductor's score and complete set of instrumental parts; a sample program; set and costume designs; and detailed instructions for producing the show using whatever materials are at hand. Unlike the other "Blueprint Specials," it includes no information on the librettists, songwriters, and other staff who worked on the show.

A book about Col. William N. Selig's career as an early cinematic pioneer and movie director and founder of the film industry that became Hollywood in Los Angeles.

We have found that there is a limited range of solid solutions between the skutterudite compounds CoSb{sub 3} and RuSb{sub 2}Te (about 5% on each side). For the system (RuSb{sub 2}Te){sub x}(CoSb{sub 3}){sub 1-x}, preliminary results obtained on one n-type sample on the CoSb{sub 3}-rich side show that these alloys have good thermoelectric properties and a maximum ZT of about 0.89 was obtained at about 600 C. More experiments will be started to investigate the possibility of a broader range of miscibility in this system which would allow an even further decrease in the lattice thermal conductivity, resulting in better thermoelectric properties. IrSb{sub 3} and RuSb{sub 2}Te form a complete range of solid solutions. Hot-pressed samples in this system have shown p-type conductivity. The thermoelectric properties of these p-type alloys have been measured and results have shown that their potential for thermoelectric applications is limited mainly because of the relatively low Seebeck coefficient values for p-type materials. Efforts will be directed on preparing n-type samples of the same alloys by doping with various dopants such as Ni and Pd.

From Introduction: "In connection with the fuel investigations conducted by the Bureau of Mines much information has been accumulated as to the smoke abatement activities in various cities. The essential features of the information are presented in this report, which, it is believed, will be of public interest and benefit, especially to those communities that are just beginning organized effort to abate unnecessary smoke."

From Introduction: "This bulletin updates and summarizes research recovering tungsten from Searles Lake brines, the largest known single domestic tungsten deposit."